Fixes issues where the MySQL 'REVOKE ALL PRIVILEDGES' syntax was not being run correctly due to the bound parameters, changed the code back for this statement only to run a raw query on the DB to ensure these permissions are revoked correctly, the query parameter values (username and db name) are coming from a prepared and sanitised record set therefore direct sanitization in this instance is not an issue. This fixes bug #483 (http://bugs.zpanelcp.com/view.php?id=483). Tested as working on my development enviroment.